In many locations, it is often considered desirable to be able to provide indirect and/or direct general or ambient lighting as well as track or accent lighting. Combined illumination of this nature is often used, for example, in an architect's office or in a house in which accent lighting is used to highlight a selected area, such as one on which a painting is hung, or in a commercial establishment to highlight or concentrate light on merchandise offered for sale.
Ambient lighting fixtures or luminaires typically operate at one voltage, e.g. 277 volts, whereas accent or track lighting typically operates at a lower voltage, e.g. 120 volts. In a typical lighting fixture installation, a channel is secured to the ceiling and a luminaire is mounted to the channel for support and to receive electrical connection to the building electrical power supply. The known mounting channels typically, however, only provide support for a single type of lighting and do not provide more than a single operating voltage.
It is also often desirable for a lighting designer to be able to configure the building or room lighting system so as to provide the optimum combination of direct and indirect lighting as well as access lighting in certain areas. The known mounting channels have limited flexibility of use in that they are typically of a single length, and limited as to the locations and configurations in which they can be used.